A.R.S. § 33-1473: Selfhelp for minor defects

A. If the landlord fails to comply with section 33-1434, the tenant may recover damages for the breach under section 33-1471, subsection B, or may notify the landlord of his intention to correct the condition at the landlord's expense. After being notified by the tenant in writing, if the landlord fails to comply within twenty days or as promptly thereafter as conditions require in case of emergency, the tenant may cause the work to be done by a licensed contractor and, after submitting to the landlord an itemized statement and a waiver of lien, deduct from his rent the actual and reasonable cost of the work.

B. A tenant may not repair at the landlord's expense if the condition was caused by the deliberate or negligent act or omission of the tenant, a member of his family or other person on the premises with his consent.